In order to clarify the relationship between shallow sea redox changes and biological recovery in the Late Permian, and to reveal the deep connection between oceanic hypoxia and contemporaneous climate tectonic events, a study was conducted on the Wujiaping period of the Shangsi section on the northern edge of the Yangtze River in the Late Permian. A total of 38 samples were collected, including 23 samples from the Wujiaping Formation and 15 samples from the lower part of the Dalong Formation. Divide all samples into two parts for (1) carbon oxygen isotope analysis and (2) analysis of major and trace elements in carbonate rocks.
Testing together, methods and processes: 1 The carbon and oxygen isotope analysis was completed at Nanjing Hongchuang Exploration Technology Service Company. The specific experimental procedure is to fill the carbonate powder into a 12 mL round bottom borosilicate container, place it in a 72 ℃ constant temperature sample plate, and react it with anhydrous phosphoric acid. The extracted CO2is sent to a stable isotope mass spectrometer using helium gas as the carrier, and each sample is purged a total of 10 times. The geochemical analysis of trace elements in carbonate rocks was completed at the Guangzhou Ausilicon Mineral Laboratory. Dissolve 0.05g of sample powder in 1 M acetic acid in an ultrasonic water bath at 30 ℃ for 30 minutes, then leave the solution at room temperature for 12 hours. Centrifuge and wash the solution three times, dry the residue, and weigh to calculate the dissolution percentage. Subsequently, the supernatant was evaporated to near dryness at 120 ℃ and dissolved again in 0.2M HNO3.
We selected the Wujiaping Formation in the Shangsi section of the northern margin of the Yangtze River with high-resolution time frame constraints as the research object, conducted sedimentological and sedimentary geochemical studies, and reconstructed the marine redox environment during the Late Permian Wujiaping period.
The carbon and oxygen isotope testing uses four national standards (GBW04405, GBW04406, GBW04416, and GBW04417) to calibrate the samples. According to the VPDB standard, the standard deviation of δ13Ccarbis better than 0.01 ‰. Trace element analysis was conducted on American PE 5300V. The analysis process adopts national standards GBW07314, GBW07315, GBW07316, and the US Geological Survey basalt standard material 6BHVO-2 for quality monitoring. The relative error of most element results is less than 5%.
| # | number | name | type |
| 1 | 42402120，42272132 | National Natural Science Foundation of China | |
| 2 | 20200-000526-04 | other | |
| 3 | 80000-2024ZF11402 | other |
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CSTR:11738.11.NCDC.GEOCHEM.DB6688.2024
10.12072/ncdc.geochem.db6688.2024